Discover and notify mac address of device is important.
In many environments hosts are mainly managed by dhcp service.
Then for inventory only MAC address may be used for host reference !.

MAC address may be available for example by shell call

exec("arp

") return for example:

10.1.1.45 ether 02:XX:YY:ZZ:63:1C C eth0

After implementing store MAC for host would be interesting:
1. Show MAC in list: Monitoring >> Discovery

2. Implement trigger for firing by change MAC address

I hope this may be useful also to other Zabbix users

Janusz